N等分圆，正N边形，圆的内接正N边形，外接正N边形代码,C代码库,德仔网

代码语言

代码分类

【C】 N等分圆，正N边形，圆的内接正N边形，外接正N边形

作者:参天 / 发布于2014/7/17/ 860

N等分圆，正N边形，圆的内接正N边形，外接正N边形


	void CMyDlg::OnButton2()
	{
	// TODO: Add your control notification handler code here
	CDC *pDC;
	pDC = this->GetDC();
	int iList[100];
	iList[0]=1; //费氏数列初始的两个元素
	iList[1]=1;
	int i;
	int ix; //横坐标的整数点
	int iy; //纵坐标的整数点
	double dR=200; //半径
	int iStart=300;
	int iNum=9; //画几边形；10个圆就是，10-1边形
	
	double dx,dy;
	double dPi = 3.1415926535; //&pi;，2&pi;是一个圆周
	double dPercision = 0.01; //精度0.01弧度 数值小，越像多边形
	double da=0; //角度
	dx = cos(da)*dR; //取得XY坐标，cos和sin呼唤，可以改变旋转方向，目前是顺时针
	dy = sin(da)*dR;
	ix = int(dx); //取整
	iy = int(dy);
	pDC->MoveTo(iStart+ix, iStart+iy);
	for(da=0; da<=2*dPi; da+=dPercision) //画圆
	{
	 dx = cos(da)*dR;
	 dy = sin(da)*dR;
	 ix = int(dx);
	 iy = int(dy);
	 pDC->LineTo(iStart+ix, iStart+iy);
	}
	i=0;
	dPercision = 2*dPi/9.00001; //画内接九边形
	for(da=0; da<=2*dPi; da+=dPercision)
	{
	 dx = cos(da)*dR;
	 dy = sin(da)*dR;
	 ix = int(dx);
	 iy = int(dy);
	 iList[i++]=ix;
	 iList[i++]=iy;
	 pDC->LineTo(iStart+ix, iStart+iy);
	 pDC->LineTo(iStart, iStart);
	 pDC->LineTo(iStart+ix, iStart+iy);
	}
	i=0;
	dPercision = 2*dPi/9.00001; //画外接九边形
	dR=dR/sin(dPi-dPercision/2-dPi/2);//(半径变化)
	for(da=0; da<=2*dPi; da+=dPercision)
	{
	 dx = cos(da)*dR;
	 dy = sin(da)*dR;
	 ix = int(dx);
	 iy = int(dy);
	 iList[i++]=ix;
	 iList[i++]=iy;
	 pDC->LineTo(iStart+ix, iStart+iy);
	 pDC->LineTo(iStart, iStart);
	 pDC->LineTo(iStart+ix, iStart+iy);
	}
	pDC->SetTextColor(RGB(255, 0, 0));
	i=0;
	dPercision = 2*dPi/9.00001; //画外接九边形
	//dR=dR/sin(dPi-dPercision/2-dPi/2);
	for(da=dPercision/2; da<=2*dPi+dPercision/2; da+=dPercision)//转动半顶角个角
	{
	 dx = cos(da)*dR;
	 dy = sin(da)*dR;
	 ix = int(dx);
	 iy = int(dy);
	 iList[i++]=ix;
	 iList[i++]=iy;
	 pDC->LineTo(iStart+ix, iStart+iy);
	 pDC->LineTo(iStart, iStart);
	 pDC->LineTo(iStart+ix, iStart+iy);
	}

试试其它关键字

同语言下

可能有用的

参天贡献的其它代码(1)

.N等分圆，正N边形，圆的内接正N边形，外接正N边形